1. The Field of the Invention
The present invention relates to the field of network communication. More specifically, the present invention relates to establishing a secure connection to a private corporate network over a public network without being restricted to communication through the private corporate network.
2. The Prior State of the Art
The Internet has transformed the way people communicate and do business. For example, electronic mail allows individuals to send electronic messages and attached documents world-wide in a matter of hours, minutes, or often even seconds. Information regarding an almost limitless amount of subjects may be retrieved from remote locations and presented to the user. Chat rooms and instant messaging allow individuals to electronically discuss various topics even though the participants are remotely located from each other.
In addition to the above forms of communication, it is often desirable for an authorized user of a private corporate network to obtain access to information in a private corporate network. For example, a user may typically use a client within a private corporate network, the corporate network being separated from the remainder of the Internet using a firewall or other security measures. That private corporate network may contain data that is interesting to the user such as documents, e-mails, and so forth. As the user travels, the user may desire to remotely access the data in the private corporate network using a client external to the private corporate network.
In order to access a private corporate network from outside of a private corporate network, one must typically establish a connection over a public network, such as, for example, the Internet. Since the data communicated between the private corporate network and the client outside the private corporate network is often sensitive in nature, the link over the public network should be secure so as to avoid eavesdropping.
One conventional protocol used to establish this secure connection over the public network is called Point-to-Point Tunneling Protocol (PPTP). PPTP allows an external client to establish a secure Virtual Private Network (VPN) link to a VPN access server within the private corporate network so as to guard against eavesdropping by those in the public network. Establishing a PPTP connection between a private corporate network and an external client is an effective and secure way to allow the external client access to resources within the private corporate network.
However, as long as the PPTP link is established using a communication device such as a network card or modem, any communication from the communication device must occur through the PPTP link. In a client that has only one active communication device, this means that the while the PPTP link is active, the client can only communicate through the PPTP link.
Thus, if the external client is to communicate with a Web site outside of the private corporate network, the client must either discontinue the PPTP link or else submit requests through the PPTP link to a VPN access server in the private corporate network (assuming the external client only has one active communications device). The VPN access server would supply the request to the proxy server in the private corporate network. The proxy server would then establish a connection to the desired Web site.
In the sense that all communications from the external client to resources outside of the private corporate network must pass through the proxy server of the private corporate network, it is as though the external client is part of the private corporate network. Thus, establishing a PPTP link to access a private corporate network restricts all communications going to and from the client to the PPTP link. This introduces inefficiencies in routing and causes the private corporate network to allocate memory and processing time to handling such requests even thought the desired resource and the external client are both outside of the private corporate network.
In addition, however, the communications going out of the private corporate network often open up the private corporate network to security breaches by individuals analyzing outgoing messages from the private corporate network. The use of PPTP forces communications from the communication device of the external client to pass through the private corporate network and possibly back out to the public network thus unnecessarily causing the private corporate network to establish communications outside of the private corporate network.
What is therefore desired are ways of allowing outside clients to establish a connection with their private corporate networks over a public network without restricting the client to communication through the private corporate network.